1 files changed, 344 insertions, 0 deletions
diff --git a/lib/librte_eal/common/malloc_elem.c b/lib/librte_eal/common/malloc_elem.c
new file mode 100644
index 00000000..27e9925d
--- /dev/null
+++ b/lib/librte_eal/common/malloc_elem.c
@@ -0,0 +1,344 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <stdint.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/queue.h>
+
+#include <rte_memory.h>
+#include <rte_eal.h>
+#include <rte_launch.h>
+#include <rte_per_lcore.h>
+#include <rte_lcore.h>
+#include <rte_debug.h>
+#include <rte_common.h>
+#include <rte_spinlock.h>
+
+#include "malloc_elem.h"
+#include "malloc_heap.h"
+
+#define MIN_DATA_SIZE (RTE_CACHE_LINE_SIZE)
+
+/*
+ * initialise a general malloc_elem header structure
+ */
+void
+malloc_elem_init(struct malloc_elem *elem,
+		struct malloc_heap *heap, const struct rte_memseg *ms, size_t size)
+{
+	elem->heap = heap;
+	elem->ms = ms;
+	elem->prev = NULL;
+	memset(&elem->free_list, 0, sizeof(elem->free_list));
+	elem->state = ELEM_FREE;
+	elem->size = size;
+	elem->pad = 0;
+	set_header(elem);
+	set_trailer(elem);
+}
+
+/*
+ * initialise a dummy malloc_elem header for the end-of-memseg marker
+ */
+void
+malloc_elem_mkend(struct malloc_elem *elem, struct malloc_elem *prev)
+{
+	malloc_elem_init(elem, prev->heap, prev->ms, 0);
+	elem->prev = prev;
+	elem->state = ELEM_BUSY; /* mark busy so its never merged */
+}
+
+/*
+ * calculate the starting point of where data of the requested size
+ * and alignment would fit in the current element. If the data doesn't
+ * fit, return NULL.
+ */
+static void *
+elem_start_pt(struct malloc_elem *elem, size_t size, unsigned align,
+		size_t bound)
+{
+	const size_t bmask = ~(bound - 1);
+	uintptr_t end_pt = (uintptr_t)elem +
+			elem->size - MALLOC_ELEM_TRAILER_LEN;
+	uintptr_t new_data_start = RTE_ALIGN_FLOOR((end_pt - size), align);
+	uintptr_t new_elem_start;
+
+	/* check boundary */
+	if ((new_data_start & bmask) != ((end_pt - 1) & bmask)) {
+		end_pt = RTE_ALIGN_FLOOR(end_pt, bound);
+		new_data_start = RTE_ALIGN_FLOOR((end_pt - size), align);
+		if (((end_pt - 1) & bmask) != (new_data_start & bmask))
+			return NULL;
+	}
+
+	new_elem_start = new_data_start - MALLOC_ELEM_HEADER_LEN;
+
+	/* if the new start point is before the exist start, it won't fit */
+	return (new_elem_start < (uintptr_t)elem) ? NULL : (void *)new_elem_start;
+}
+
+/*
+ * use elem_start_pt to determine if we get meet the size and
+ * alignment request from the current element
+ */
+int
+malloc_elem_can_hold(struct malloc_elem *elem, size_t size,	unsigned align,
+		size_t bound)
+{
+	return elem_start_pt(elem, size, align, bound) != NULL;
+}
+
+/*
+ * split an existing element into two smaller elements at the given
+ * split_pt parameter.
+ */
+static void
+split_elem(struct malloc_elem *elem, struct malloc_elem *split_pt)
+{
+	struct malloc_elem *next_elem = RTE_PTR_ADD(elem, elem->size);
+	const size_t old_elem_size = (uintptr_t)split_pt - (uintptr_t)elem;
+	const size_t new_elem_size = elem->size - old_elem_size;
+
+	malloc_elem_init(split_pt, elem->heap, elem->ms, new_elem_size);
+	split_pt->prev = elem;
+	next_elem->prev = split_pt;
+	elem->size = old_elem_size;
+	set_trailer(elem);
+}
+
+/*
+ * Given an element size, compute its freelist index.
+ * We free an element into the freelist containing similarly-sized elements.
+ * We try to allocate elements starting with the freelist containing
+ * similarly-sized elements, and if necessary, we search freelists
+ * containing larger elements.
+ *
+ * Example element size ranges for a heap with five free lists:
+ *   heap->free_head[0] - (0   , 2^8]
+ *   heap->free_head[1] - (2^8 , 2^10]
+ *   heap->free_head[2] - (2^10 ,2^12]
+ *   heap->free_head[3] - (2^12, 2^14]
+ *   heap->free_head[4] - (2^14, MAX_SIZE]
+ */
+size_t
+malloc_elem_free_list_index(size_t size)
+{
+#define MALLOC_MINSIZE_LOG2   8
+#define MALLOC_LOG2_INCREMENT 2
+
+	size_t log2;
+	size_t index;
+
+	if (size <= (1UL << MALLOC_MINSIZE_LOG2))
+		return 0;
+
+	/* Find next power of 2 >= size. */
+	log2 = sizeof(size) * 8 - __builtin_clzl(size-1);
+
+	/* Compute freelist index, based on log2(size). */
+	index = (log2 - MALLOC_MINSIZE_LOG2 + MALLOC_LOG2_INCREMENT - 1) /
+	        MALLOC_LOG2_INCREMENT;
+
+	return index <= RTE_HEAP_NUM_FREELISTS-1?
+	        index: RTE_HEAP_NUM_FREELISTS-1;
+}
+
+/*
+ * Add the specified element to its heap's free list.
+ */
+void
+malloc_elem_free_list_insert(struct malloc_elem *elem)
+{
+	size_t idx;
+
+	idx = malloc_elem_free_list_index(elem->size - MALLOC_ELEM_HEADER_LEN);
+	elem->state = ELEM_FREE;
+	LIST_INSERT_HEAD(&elem->heap->free_head[idx], elem, free_list);
+}
+
+/*
+ * Remove the specified element from its heap's free list.
+ */
+static void
+elem_free_list_remove(struct malloc_elem *elem)
+{
+	LIST_REMOVE(elem, free_list);
+}
+
+/*
+ * reserve a block of data in an existing malloc_elem. If the malloc_elem
+ * is much larger than the data block requested, we split the element in two.
+ * This function is only called from malloc_heap_alloc so parameter checking
+ * is not done here, as it's done there previously.
+ */
+struct malloc_elem *
+malloc_elem_alloc(struct malloc_elem *elem, size_t size, unsigned align,
+		size_t bound)
+{
+	struct malloc_elem *new_elem = elem_start_pt(elem, size, align, bound);
+	const size_t old_elem_size = (uintptr_t)new_elem - (uintptr_t)elem;
+	const size_t trailer_size = elem->size - old_elem_size - size -
+		MALLOC_ELEM_OVERHEAD;
+
+	elem_free_list_remove(elem);
+
+	if (trailer_size > MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
+		/* split it, too much free space after elem */
+		struct malloc_elem *new_free_elem =
+				RTE_PTR_ADD(new_elem, size + MALLOC_ELEM_OVERHEAD);
+
+		split_elem(elem, new_free_elem);
+		malloc_elem_free_list_insert(new_free_elem);
+	}
+
+	if (old_elem_size < MALLOC_ELEM_OVERHEAD + MIN_DATA_SIZE) {
+		/* don't split it, pad the element instead */
+		elem->state = ELEM_BUSY;
+		elem->pad = old_elem_size;
+
+		/* put a dummy header in padding, to point to real element header */
+		if (elem->pad > 0){ /* pad will be at least 64-bytes, as everything
+		                     * is cache-line aligned */
+			new_elem->pad = elem->pad;
+			new_elem->state = ELEM_PAD;
+			new_elem->size = elem->size - elem->pad;
+			set_header(new_elem);
+		}
+
+		return new_elem;
+	}
+
+	/* we are going to split the element in two. The original element
+	 * remains free, and the new element is the one allocated.
+	 * Re-insert original element, in case its new size makes it
+	 * belong on a different list.
+	 */
+	split_elem(elem, new_elem);
+	new_elem->state = ELEM_BUSY;
+	malloc_elem_free_list_insert(elem);
+
+	return new_elem;
+}
+
+/*
+ * joing two struct malloc_elem together. elem1 and elem2 must
+ * be contiguous in memory.
+ */
+static inline void
+join_elem(struct malloc_elem *elem1, struct malloc_elem *elem2)
+{
+	struct malloc_elem *next = RTE_PTR_ADD(elem2, elem2->size);
+	elem1->size += elem2->size;
+	next->prev = elem1;
+}
+
+/*
+ * free a malloc_elem block by adding it to the free list. If the
+ * blocks either immediately before or immediately after newly freed block
+ * are also free, the blocks are merged together.
+ */
+int
+malloc_elem_free(struct malloc_elem *elem)
+{
+	if (!malloc_elem_cookies_ok(elem) || elem->state != ELEM_BUSY)
+		return -1;
+
+	rte_spinlock_lock(&(elem->heap->lock));
+	struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
+	if (next->state == ELEM_FREE){
+		/* remove from free list, join to this one */
+		elem_free_list_remove(next);
+		join_elem(elem, next);
+	}
+
+	/* check if previous element is free, if so join with it and return,
+	 * need to re-insert in free list, as that element's size is changing
+	 */
+	if (elem->prev != NULL && elem->prev->state == ELEM_FREE) {
+		elem_free_list_remove(elem->prev);
+		join_elem(elem->prev, elem);
+		malloc_elem_free_list_insert(elem->prev);
+	}
+	/* otherwise add ourselves to the free list */
+	else {
+		malloc_elem_free_list_insert(elem);
+		elem->pad = 0;
+	}
+	/* decrease heap's count of allocated elements */
+	elem->heap->alloc_count--;
+	rte_spinlock_unlock(&(elem->heap->lock));
+
+	return 0;
+}
+
+/*
+ * attempt to resize a malloc_elem by expanding into any free space
+ * immediately after it in memory.
+ */
+int
+malloc_elem_resize(struct malloc_elem *elem, size_t size)
+{
+	const size_t new_size = size + MALLOC_ELEM_OVERHEAD;
+	/* if we request a smaller size, then always return ok */
+	const size_t current_size = elem->size - elem->pad;
+	if (current_size >= new_size)
+		return 0;
+
+	struct malloc_elem *next = RTE_PTR_ADD(elem, elem->size);
+	rte_spinlock_lock(&elem->heap->lock);
+	if (next ->state != ELEM_FREE)
+		goto err_return;
+	if (current_size + next->size < new_size)
+		goto err_return;
+
+	/* we now know the element fits, so remove from free list,
+	 * join the two
+	 */
+	elem_free_list_remove(next);
+	join_elem(elem, next);
+
+	if (elem->size - new_size >= MIN_DATA_SIZE + MALLOC_ELEM_OVERHEAD){
+		/* now we have a big block together. Lets cut it down a bit, by splitting */
+		struct malloc_elem *split_pt = RTE_PTR_ADD(elem, new_size);
+		split_pt = RTE_PTR_ALIGN_CEIL(split_pt, RTE_CACHE_LINE_SIZE);
+		split_elem(elem, split_pt);
+		malloc_elem_free_list_insert(split_pt);
+	}
+	rte_spinlock_unlock(&elem->heap->lock);
+	return 0;
+
+err_return:
+	rte_spinlock_unlock(&elem->heap->lock);
+	return -1;
+}